Measurement of Neutrino Oscillation with KamLAND: Evidence of Spectral Distortion
Language
en
Article de revue
This item was published in
Physical Review Letters. 2005, vol. 94, p. 081801
American Physical Society
English Abstract
We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 [overline nu ]e candidate events with energies above 3.4 MeV compared to 365.2±23.7 ...Read more >
We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 [overline nu ]e candidate events with energies above 3.4 MeV compared to 365.2±23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8±7.3 expected background events, the statistical significance for reactor [overline nu ]e disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from [overline nu ]e oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam2=7.9<sub>-0.5</sub><sup>+0.6</sup>×10-5 eV2. A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam2=7.9<sub>-0.5</sub><sup>+0.6</sup>×10-5 eV2 and tan2theta=0.40<sub>-0.07</sub><sup>+0.10</sup>, the most precise determination to date.Read less <
Origin
Hal imported